The SS for Kagerou, she usually seems phased out but is clever and well knowing about important details. She is able to transform into a Gashadokuro (Large skeleton) and loves tasty foods. She’s also very good at cooking.
She gets attacked by Inugami and falls into a coma for several months. When she wakes up, she transforms into her yokai form and can’t return to her human form thanks to Inugami, who put a curse on her and caused her death. This event leads up to Soushi’s death and the consequent death of the rest.
Second Arc (23 years later): She is 20 years old. Karuta is currently Watanuki’s SS in this timeline. It is said that she became a very good business woman before becoming an SS. Along with this, she remembers her previous life with Watanuki, her death, and living in the mansion with everyone else. She is determined to stop Inugami this time around alongside Renshou, Natsume, Kagerou, and Nobara because she wants everyone to become grandmas and grandpas together.
She stopped Kagerou from going to the past to stop Inugami because she didn’t want him to be alone.
After telling Watanuki about their past lives, she mentions that she isn’t afraid of reincarnating again because she read the contents of the letter that Watanuki wrote for the time capsule, which state that Watanuki will always protect her.